Locks of this kind operate very smoothly during closing and generally during opening, and have improved convenience. In fact, upon closing a door, hatch or the like, the user need merely manually move the door, or the like to approximately its closing position, and the assist means will automatically intervene and on their own will effect the closure of the door. These assist means are generally electrical.
The various embodiments of this type of lock proposed thus far, particularly in U.S. Pat. No. 3,332,713, are relatively complicated and bulky, especially in terms of the means making it possible to assure opening and closing in the event of failure of the assisting motive means.